/*

* Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: Definition for mailbox cache

*

*/

#ifndef EMAILMAILBOXCACHE_H

#define EMAILMAILBOXCACHE_H

#include <e32base.h> 

#include <emailapidefs.h>

using namespace EmailInterface;

class CPluginData;

/**

* Cache associating mailbox with a protocol plugin. Improves performance by

* removing need to load protocol plugins every time a mailbox needs to be

* accessed (and keeping plugin loaded when it is not needed)

* @since s60 v5.2

*/

NONSHARABLE_CLASS( CEmailMailboxCache ) : public CBase

{

public:

    /**

    * Cache entry to access plugin by mailbox id

    */

    class TCacheEntry

    {

    public:

        inline TCacheEntry( 

            CPluginData* aPluginData, 

            TMailboxId aId ) : 

            iPluginData( aPluginData ), 

            iMailboxId( aId ) {}

        CPluginData* iPluginData;

        TMailboxId iMailboxId;

    };

    /**

    * Constructor

    */

    static CEmailMailboxCache* NewL();

    /** destructor */

    ~CEmailMailboxCache();

    /**

    * Clears cache and indicates that one or more AddMailboxL calls will 

    * follow.

    * Cleanup support invalidates cache if leave occurs before EndCachingPop()

    * is called

    */

    void StartCachingPushL();

    /**

    * Marks caching fully complete for all mailboxes (call when no more

    * AddMailboxL will follow) and pops cleanup item.

    */

    void EndCachingPop();      

    /**

    * Returns if mailboxes are cached

    */

    TBool IsCached() const;

    /**

    * Adds mailbox to cache.

    * @param aPluginData mailbox associated with plugin(data)

    * @param aMailboxId mailbox id

    * @precondition: StartCaching must have been called. 

    */

    void AddMailboxL( CPluginData& aPluginData, const TMailboxId& aMailboxId );

    /**

    * Returns plugin data by mailbox id

    * @param aMailboxId 

    * @return plugin data associated with specified mailbox

    */

    CPluginData* PluginDataL( const TMailboxId& aMailboxId ) const;

    /**

    * Returns plugin data by plugin id

    * @param aPluginId 

    * @return plugin data associated with specified plugin

    */

    CPluginData* PluginDataL( const TUid& aPluginId ) const;

    /**

    * Gets all mailbox ids in all protocol plugins

    */

    void GetIdsL( REmailMailboxIdArray& aIdArray ) const;

private:    

    TInt FindById( const TMailboxId& aMailboxId ) const;

    TInt FindByPluginIdL( const TUid& aPluginId ) const;    

    static TBool Equals( const TCacheEntry& a1, const  TCacheEntry& a2 );

    static TBool PluginEquals( const TCacheEntry& a1, const  TCacheEntry& a2 );

    static void CleanupOp( TAny* aAny );

private:

    CEmailMailboxCache();

    void ConstructL();

    enum TCacheState {

        EEmpty,

        ECaching,

        EComplete

    };

private:

    // empty, caching or caching complete

    TCacheState iState;

    // cached mailbox id with associated plugin data

    RArray<TCacheEntry> iEntries;

};

#endif // EMAILMAILBOXCACHE_H

// End of file